Figure 7.

The functional glutamatergic drive onto trigeminal motoneurons during waking and phasic REM is mediated primarily by non-NMDA receptors. A, Group data (n = 6) demonstrating that antagonism of non-NMDA receptors by perfusion of 0.5 mm CNQX into the left trigeminal motor pool significantly decreased left masseter muscle tone during waking but had no effect on levels of masseter tone during either NREM (p = 0.939) or tonic REM (p = 0.985) sleep. B, C, This same intervention significantly decreased the number of muscle twitches during phasic REM sleep and the magnitude of the remaining muscle twitches. D, Group data (n = 5) demonstrating that antagonism of NMDA receptors by perfusion of 5.0 mm d-AP-5 into the left trigeminal motor pool significantly decreased left masseter muscle tone during waking by 49% but had no effect on levels of masseter tone during either NREM (p = 0.896) or tonic REM (p = 0.974) sleep. E, F, This same intervention did not decrease the number of muscle twitches during REM sleep (p = 0.231) or the amplitude of muscle twitches (p = 0.197). All values are means ± SEM; *p < 0.05 and **p < 0.001; A.U., arbitrary units.